U.S. flagAn official website of the United States government
                    Here's how you know **Official websites use .gov**
                            
                            A **.gov** website belongs to an official government organization in the United States.
 **Secure .gov websites use HTTPS**
                            
                            A **lock** (                            
                              A locked padlock                                                      
                            
                            ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Menu Agricultural Research Service
						
                    U.S. DEPARTMENT OF AGRICULTURE
 close



Research
                Research Home
                            National Programs
                            Research Projects
                            Scientific Manuscripts
                            International Engagement
                            Scientific Software/Models
                            Databases and Datasets
                            Office of Scientific Quality Review
            Media
                News & Features
                            Multimedia
                            Briefing Room
                            Down on the Farm
                            Press Room
                            Science in Your Shopping Cart
                            Scientific Discoveries
                            Tellus
                            Under the Microscope
            About ARS
                About ARS Home
                            Staff Directory
                            Labs and Research Centers (Map)
                            Headquarter Offices
                            Organizational Chart
                            Employee Services (REE Employees Only)
                            Office of Outreach, Diversity, and Equal Opportunity
            Work With Us
                Work With Us Home
                            ARS Vacancies at USAJOBS
                            Careers at ARS Information
                            Scientific Collaborations
                            Extramural Agreements
                            1890 Faculty Research Sabbatical ProgramSearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home News & Events News Articles Research News 2003





- ARS News & Events
- AgResearch Magazine
- Image Gallery
- News
- Search News & Events
- Pesticide Drift May Endanger Pollinators
- ARS Seeks a Fire Ant Fix
- Scientific Discoveries 2024
- ARS Featured Photos
- Down on the Farm
- Facebook Live Events
- Food and Nutrition Research Briefs
- News Archive
- Science in Your Shopping Cart
- Scientific Discoveries
- Social Media
- Under the Microscope
- AgResearch magazine
- ARS at Work
- ARS Memorial Lectures
- ARS Science Hall of Fame
- Citrus Disease (Huanglongbing)
- Contact Office of Communications
- Plant Hardiness Zone Map
- Mobile Apps
- Public Affairs Contacts
- Publications and Other Resources
- USDA Blog
- Videos

Archived Page
 This page has been archived and is being provided for reference purposes only. The page is no longer being updated, and therefore, links on the page may be invalid.
 New Finding on Bacterium Linked to Disease of Orange, Grapes By Rosalie Marion BlissJuly 31, 2003 WASHINGTON, July 31--A type of bacterium that scientists previously thought was spread only by insect vectors has now been found to be transmitted by seeds to seedlings, according to Agricultural Research Service scientists and cooperators in Brazil. For 60 years, experts have believed that the bacterium, named Xylella fastidiosa, is spread only by insects such as the glassy-winged sharpshooter, or through contaminated bud wood. Xylella bacteria have various strains which are known to cause several diseases, such as citrus variegated chlorosis (CVC) in Brazilian oranges, coffee leaf scorch in South America and Pierce's disease of grapevines in North and Central America--leading to substantial yield reductions. ARS plant pathologist John Hartung and colleagues reported this month that X. fastidiosa can infect and colonize orange fruit tissues and seeds, and that the bacterium transmits from infected seeds to seedlings. The finding is reported as the first known demonstration that Xylella can infect plants via seed. Hartung, with the ARS Fruit Laboratory in Beltsville, Md., and collaborators from the University of Sao Paulo, Brazil, reported the findings in the August issue of Phytopathology. ARS is the U.S. Department of Agriculture's chief in-house scientific research agency. "The implication that X. fastidiosa could propagate itself within other plant species through seed, from generation to generation, is a change in paradigm," said Edward B. Knipling, acting ARS administrator. The idea of this significant new route of transmission casts new light on another finding reported last year. In greenhouse experiments, Hartung and collaborators in Brazil unexpectedly found that the strain of X. fastidiosa that causes disease in Brazilian sweet orange also causes symptoms of Pierce's disease in grapes. "We knew that the strain in orange was genetically different from the one in grapes, so we had assumed that it would not be able to also cause disease in grapes," said Hartung. The CVC strain thus could become a threat to U.S. orange and grape growers.


Return to top


Research
                            Media
                            About ARS
                            Work With Us


Connect with ARS Sign up


ARS Home
                            USDA.gov
                            Plain Writing
                            Policies & Links
                            Civil Rights Statements
                            FOIA
                            Accessibility Statement
                            Privacy Policy
                            Non-Discrimination Statement
                            Quality of Information
                            USA.gov
                            WhiteHouse.gov